Field of Invention
Various embodiments of the inventive concept of the present disclosure relate to a system and method for providing a virtual desktop service using a cache server.
Description of Related Art
A VDI (Virtual Desktop Infrastructure) system that supports virtual desktop services enables systematic storage and management of OS of virtual machines that users use, and applications and data that the users create all in a storage connected to a central server backend, and enables the users to remotely access the system using the CPU and memory resources of the host server so that they could perform necessary operations as if the system is their desktop environment.
Such a VDI system is advantageous in that it can respond to security problems such as by preventing information leakage, and can manage resources intensively. In a VDI system, however, all the I/O that a user executes require operations of inputting/outputting into/from a storage, unlike in a PC environment, and thus frequent operations of inputting/outputting into/from such a storage become the largest bottleneck section, leading to a problem that the responding performance of the system that the user senses must be supported such that it is similar to the performance when using a personal PC.
Especially, in the case a user uses an application, if an access to the storage is delayed, the performance that the user senses may deteriorate significantly compared to the PC environment, and thus such a delay must be prevented. Furthermore, operations such as boot/log in storm, and simultaneous virus scan and the like that occur at the point where most users of the VDI system start their work generate load of about 10 times that of a normal state, and thus the system must be designed to guarantee the responsiveness of the system in such a case as well.
In order to resolve the aforementioned problems, a multi-step cache structure using SSD and the like is being suggested, and a method for improving the performance by having a cache in the host server is being suggested as well. However, these are only methods for improving the cache performance for general purpose. Therefore, there needs to be an optimized structure and method where the characteristics of VDI are reflected, and in order to improve the performance of the VDI environment, a prefetching technology where the characteristics of the VDI workload are reflected may be effective. A method suggested so far is a method of preparing for a sudden rise by reading ahead in a read cache that consists of a fast medium such as SSD even before using all data predicted as necessary. However, considering the problem of the capacity of the cache, there is difficulty in pre-reading all the data.